Towing a Travel Trailer: Weight, Hitches and Brakes

Towing a travel trailer safely comes down to three things: the loaded trailer must stay within the tow vehicle’s ratings, the hitch and brake equipment must be rated for the load, and the trailer must be loaded so it tracks straight. Get any of those wrong and the rig is unstable no matter how carefully it is driven. A used trailer adds a fourth: the tires, brakes and hitch hardware may be older than they look, so they need checking before the first trip, not after.

The weight ratings, decoded

Every rating below is set by the manufacturer and printed on a label on the vehicle. None of them can be raised by adding parts. Four-wheel drive, for example, adds weight, cost and parts to maintain but does not raise the vehicle’s weight ratings.

Water weighs about 8.3 pounds per gallon and propane about 4.2 pounds per gallon, so a full fresh tank and two full cylinders are real weight, not a rounding error. The only way to know actual weight is a public scale: weigh fully loaded, by axle where possible.

Can my truck tow this camper?

The question is not just whether the truck can pull the trailer. It is whether the truck can carry the tongue weight and stay under GCWR with everything loaded.

Start with the tire and loading label on the driver’s door jamb. That payload figure must cover passengers, cargo, the hitch and the tongue or pin weight. A trailer that is within the tow rating can still overload the truck’s rear axle and payload once the family, the cooler and the hitch are aboard.

Then check GCWR: the loaded truck plus the loaded trailer. Use the trailer’s GVWR as a stand-in for its loaded weight rather than the dry weight, because the dry figure leaves out water, propane, batteries and gear. If the numbers are close, weigh the rig before committing.

A used trailer should be checked for weight-label presence and condition. Labels fade, peel or go missing, and without them the ratings have to be confirmed another way.

Travel trailer or fifth wheel

A travel trailer hitches to a ball mount on the tow vehicle’s receiver or bumper, a “bumper pull.” A fifth wheel has a raised front section that rests over the bed of a pickup on a fifth-wheel hitch, so part of its weight sits over or just ahead of the truck’s rear axle. That placement usually makes a fifth wheel more stable to tow, but it needs a pickup truck and takes up the bed. Sizes and floor plans differ too. Used travel trailers vs fifth wheels covers the trade-offs in more detail.

Hitches and weight distribution

A weight-distributing hitch spreads tongue weight across the tow vehicle’s and trailer’s axles. Sway control resists trailer sway. Never use a hitch, ball or receiver rated below the load.

On a used trailer, inspect the coupler, the safety chains, the breakaway switch and the hitch head for wear, rust and bent parts. A weight-distribution hitch that was set up for a different truck may need adjusting for yours; the bars should be sized to the tongue weight, not picked by guesswork.

Safety chains are crossed under the tongue. The breakaway switch applies the trailer’s brakes if it comes off the tow vehicle, and it only works if its battery is charged and the cable is connected properly.

Brakes and the brake controller

Trailers with electric brakes need a brake controller in the tow vehicle. Many states require trailer brakes and a breakaway system above a weight they set; check your state DMV. The controller should be adjusted so the trailer brakes lead slightly without locking the wheels on dry pavement, and the setting changes with load.

On a used trailer, have a qualified technician pull a wheel and check the brake linings, drums, magnets and wiring. Sitting trailers seize brake components and corrode wiring. A trailer that has been parked for seasons may look fine and brake poorly.

Tires on a used trailer

ST (special trailer) tires are for trailer axles only, and ST tires without a speed rating are limited to 65 mph. The DOT code on the sidewall ends in four digits giving week and year of manufacture: 2419 means the 24th week of 2019. RV tires often age out before the tread wears out; common guidance is a yearly inspection once tires are 5 years old and replacement no later than 10 years from the date of manufacture, whatever the tread looks like. Inflate to the pressure for the actual load, from the tire maker’s load and inflation table or the vehicle’s tire placard, measured cold. RV tires: age, load and pressure explains how to read the codes and set pressures.

Sway: what causes it and how to prevent it

Sway is the trailer wagging side to side behind the tow vehicle. It is usually a loading problem first and an equipment problem second. Too little tongue weight, cargo loaded behind the trailer axles, a trailer that is nose-high, or too much speed downhill all make it worse.

Load heavy items over or slightly ahead of the trailer axles, keep the tongue weight in the recommended range, and set the hitch so the trailer rides level. If sway appears, ease off the accelerator smoothly and hold the wheel straight; if you can, apply the trailer brakes alone with the brake controller’s manual control. Do not brake the tow vehicle hard or steer sharply. A sway-control device helps, but it does not fix bad loading.

Know the size before you drive

Federal rules allow vehicles up to 102 inches (8.5 feet) wide on the National Network of highways, not counting mirrors and certain safety devices. Height limits are set by the states. Know the RV’s exact height, including roof air conditioners and antennas, and keep it written where the driver can see it.

The federal commercial driver’s license does not apply to personal-use RVs, but some states require a special non-commercial license or endorsement for long or heavy combinations. A GVWR over 26,000 pounds is a common threshold, but each state sets its own - check your state DMV.

Hookup checklist before every drive

Walk around the rig once more before pulling away, and check the lights with a helper. Your first trip in a used RV: a checklist covers what to do once you are on the road and at the campsite.

What goes wrong

• Trusting the dry weight. The UVW leaves out water, propane, batteries and gear, and options added later are often not included. Buyers who match a trailer to a truck using the dry weight can end up overloaded on the first trip.
• Ignoring payload. The tow rating gets all the attention, but the door-jamb payload is often the real limit on a half-ton pickup once passengers and tongue weight are counted.
• Buying a used trailer with old tires. Tread depth says little about age. Check the DOT date code on every tire, including the spare.
• Skipping the brake inspection. Seized brakes and corroded wiring are common on trailers that sat. Test the brakes at low speed before trusting them.
• Bad loading. Heavy gear behind the axles lightens the tongue and invites sway. Load over the axles and check tongue weight at a scale.
• A hitch rated below the load. A receiver, ball or mount that is undersized for the trailer is a failure waiting to happen.
• No weight-distribution setup. A heavy tongue without weight distribution can overload the rear axle and unload the front steering axle.
• Paperwork surprises. A branded title affects financing, insurance and resale, and a lien must be released before ownership passes. How to check an RV’s title explains the paperwork side.
• Sway at speed. If the trailer starts to wag, slow down smoothly and fix the loading before the next trip.

Towing a travel trailer is a system: ratings, hitch, brakes, tires and loading all have to work together. Check each one on the used trailer before the first drive, and recheck the weights at a scale once it is loaded for a trip.